hypre/examples/ex12f.f
2011-09-21 20:32:59 +00:00

480 lines
16 KiB
Fortran

c
c Example 12
c
c Interface: Semi-Structured interface (SStruct)
c
c Compile with: make ex12f (may need to edit HYPRE_DIR in Makefile)
c
c Sample runs: mpirun -np 2 ex12f
c
c Description: The grid layout is the same as ex1, but with nodal
c unknowns. The solver is PCG preconditioned with either PFMG or
c BoomerAMG, set with 'precond_id' below.
c
c We recommend viewing the Struct examples before viewing this and
c the other SStruct examples. This is one of the simplest SStruct
c examples, used primarily to demonstrate how to set up
c non-cell-centered problems, and to demonstrate how easy it is to
c switch between structured solvers (PFMG) and solvers designed for
c more general settings (AMG).
c
program ex12f
implicit none
include 'mpif.h'
include 'HYPREf.h'
integer ierr
integer i, j, myid, num_procs
integer*8 grid
integer*8 graph
integer*8 stencil
integer*8 A
integer*8 b
integer*8 x
integer nparts
integer nvars
integer part
integer var
integer precond_id, object_type
integer ilower(2), iupper(2)
integer vartypes(1)
integer offsets(2,5)
integer ent
integer nentries, nvalues, stencil_indices(5)
double precision values(100), tol
c This comes from 'sstruct_mv/HYPRE_sstruct_mv.h'
integer HYPRE_SSTRUCT_VARIABLE_NODE
parameter( HYPRE_SSTRUCT_VARIABLE_NODE = 1 )
integer*8 sA
integer*8 sb
integer*8 sx
integer*8 parA
integer*8 parb
integer*8 parx
integer*8 solver
integer*8 precond
character*32 matfile
c We only have one part and one variable
nparts = 1
nvars = 1
part = 0
var = 0
c Initialize MPI
call MPI_Init(ierr)
call MPI_Comm_rank(MPI_COMM_WORLD, myid, ierr)
call MPI_Comm_size(MPI_COMM_WORLD, num_procs, ierr)
if (num_procs .ne. 2) then
if (myid .eq. 0) then
print *, "Must run with 2 processors!"
stop
endif
endif
c Set preconditioner id (PFMG = 1, BoomerAMG = 2)
precond_id = 1
if (precond_id .eq. 1) then
object_type = HYPRE_STRUCT
else if (precond_id .eq. 2) then
object_type = HYPRE_PARCSR
else
if (myid .eq. 0) then
print *, "Invalid solver!"
stop
endif
endif
c-----------------------------------------------------------------------
c 1. Set up the grid. Here we use only one part. Each processor
c describes the piece of the grid that it owns.
c-----------------------------------------------------------------------
c Create an empty 2D grid object
call HYPRE_SStructGridCreate(MPI_COMM_WORLD, 2, nparts, grid,
+ ierr)
c Add boxes to the grid
if (myid .eq. 0) then
ilower(1) = -3
ilower(2) = 1
iupper(1) = -1
iupper(2) = 2
call HYPRE_SStructGridSetExtents(grid, part, ilower, iupper,
+ ierr)
else if (myid .eq. 1) then
ilower(1) = 0
ilower(2) = 1
iupper(1) = 2
iupper(2) = 4
call HYPRE_SStructGridSetExtents(grid, part, ilower, iupper,
+ ierr)
endif
c Set the variable type and number of variables on each part
vartypes(1) = HYPRE_SSTRUCT_VARIABLE_NODE
call HYPRE_SStructGridSetVariables(grid, part, nvars, vartypes,
+ ierr)
c This is a collective call finalizing the grid assembly
call HYPRE_SStructGridAssemble(grid, ierr)
c-----------------------------------------------------------------------
c 2. Define the discretization stencil
c-----------------------------------------------------------------------
c Create an empty 2D, 5-pt stencil object
call HYPRE_SStructStencilCreate(2, 5, stencil, ierr)
c Define the geometry of the stencil. Each represents a relative
c offset (in the index space).
offsets(1,1) = 0
offsets(2,1) = 0
offsets(1,2) = -1
offsets(2,2) = 0
offsets(1,3) = 1
offsets(2,3) = 0
offsets(1,4) = 0
offsets(2,4) = -1
offsets(1,5) = 0
offsets(2,5) = 1
c Assign numerical values to the offsets so that we can easily refer
c to them - the last argument indicates the variable for which we
c are assigning this stencil
do ent = 1, 5
call HYPRE_SStructStencilSetEntry(stencil,
+ ent-1, offsets(1,ent), var, ierr)
enddo
c-----------------------------------------------------------------------
c 3. Set up the Graph - this determines the non-zero structure of
c the matrix and allows non-stencil relationships between the parts
c-----------------------------------------------------------------------
c Create the graph object
call HYPRE_SStructGraphCreate(MPI_COMM_WORLD, grid, graph, ierr)
c See MatrixSetObjectType below
call HYPRE_SStructGraphSetObjectType(graph, object_type, ierr)
c Now we need to tell the graph which stencil to use for each
c variable on each part (we only have one variable and one part)
call HYPRE_SStructGraphSetStencil(graph, part, var, stencil, ierr)
c Here we could establish connections between parts if we had more
c than one part using the graph. For example, we could use
c HYPRE_GraphAddEntries() routine or HYPRE_GridSetNeighborPart()
c Assemble the graph
call HYPRE_SStructGraphAssemble(graph, ierr)
c-----------------------------------------------------------------------
c 4. Set up a SStruct Matrix
c-----------------------------------------------------------------------
c Create an empty matrix object
call HYPRE_SStructMatrixCreate(MPI_COMM_WORLD, graph, A, ierr)
c Set the object type (by default HYPRE_SSTRUCT). This determines
c the data structure used to store the matrix. For PFMG we use
c HYPRE_STRUCT, and for BoomerAMG we use HYPRE_PARCSR (set above).
call HYPRE_SStructMatrixSetObjectTyp(A, object_type, ierr)
c Get ready to set values
call HYPRE_SStructMatrixInitialize(A, ierr)
c Set the matrix coefficients. Each processor assigns coefficients
c for the boxes in the grid that it owns. Note that the
c coefficients associated with each stencil entry may vary from grid
c point to grid point if desired. Here, we first set the same
c stencil entries for each grid point. Then we make modifications
c to grid points near the boundary. Note that the ilower values are
c different from those used in ex1 because of the way nodal
c variables are referenced. Also note that some of the stencil
c values are set on both processor 0 and processor 1. See the User
c and Reference manuals for more details.
c Stencil entry labels correspond to the offsets defined above
do i = 1, 5
stencil_indices(i) = i-1
enddo
nentries = 5
if (myid .eq. 0) then
ilower(1) = -4
ilower(2) = 0
iupper(1) = -1
iupper(2) = 2
c 12 grid points, each with 5 stencil entries
nvalues = 60
else if (myid .eq. 1) then
ilower(1) = -1
ilower(2) = 0
iupper(1) = 2
iupper(2) = 4
c 12 grid points, each with 5 stencil entries
nvalues = 100
endif
do i = 1, nvalues, nentries
values(i) = 4.0
do j = 1, nentries-1
values(i+j) = -1.0
enddo
enddo
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, nentries, stencil_indices, values, ierr)
c Set the coefficients reaching outside of the boundary to 0. Note
c that both ilower *and* iupper may be different from those in ex1.
do i = 1, 5
values(i) = 0.0
enddo
if (myid .eq. 0) then
c values below our box
ilower(1) = -4
ilower(2) = 0
iupper(1) = -1
iupper(2) = 0
stencil_indices(1) = 3
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, 1, stencil_indices, values, ierr)
c values to the left of our box
ilower(1) = -4
ilower(2) = 0
iupper(1) = -4
iupper(2) = 2
stencil_indices(1) = 1
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, 1, stencil_indices, values, ierr)
c values above our box
ilower(1) = -4
ilower(2) = 2
iupper(1) = -2
iupper(2) = 2
stencil_indices(1) = 4
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, 1, stencil_indices, values, ierr)
else if (myid .eq. 1) then
c values below our box
ilower(1) = -1
ilower(2) = 0
iupper(1) = 2
iupper(2) = 0
stencil_indices(1) = 3
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, 1, stencil_indices, values, ierr)
c values to the right of our box
ilower(1) = 2
ilower(2) = 0
iupper(1) = 2
iupper(2) = 4
stencil_indices(1) = 2
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, 1, stencil_indices, values, ierr)
c values above our box
ilower(1) = -1
ilower(2) = 4
iupper(1) = 2
iupper(2) = 4
stencil_indices(1) = 4
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, 1, stencil_indices, values, ierr)
c values to the left of our box
c (that do not border the other box on proc. 0)
ilower(1) = -1
ilower(2) = 3
iupper(1) = -1
iupper(2) = 4
stencil_indices(1) = 1
call HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper,
+ var, 1, stencil_indices, values, ierr)
endif
c This is a collective call finalizing the matrix assembly
call HYPRE_SStructMatrixAssemble(A, ierr)
c matfile = 'ex12f.out'
c matfile(10:10) = char(0)
c call HYPRE_SStructMatrixPrint(matfile, A, 0, ierr)
c Create an empty vector object
call HYPRE_SStructVectorCreate(MPI_COMM_WORLD, grid, b, ierr)
call HYPRE_SStructVectorCreate(MPI_COMM_WORLD, grid, x, ierr)
c As with the matrix, set the appropriate object type for the vectors
call HYPRE_SStructVectorSetObjectTyp(b, object_type, ierr)
call HYPRE_SStructVectorSetObjectTyp(x, object_type, ierr)
c Indicate that the vector coefficients are ready to be set
call HYPRE_SStructVectorInitialize(b, ierr)
call HYPRE_SStructVectorInitialize(x, ierr)
c Set the vector coefficients. Again, note that the ilower values
c are different from those used in ex1, and some of the values are
c set on both processors.
if (myid .eq. 0) then
ilower(1) = -4
ilower(2) = 0
iupper(1) = -1
iupper(2) = 2
do i = 1, 12
values(i) = 1.0
enddo
call HYPRE_SStructVectorSetBoxValues(b, part, ilower, iupper,
+ var, values, ierr)
do i = 1, 12
values(i) = 0.0
enddo
call HYPRE_SStructVectorSetBoxValues(x, part, ilower, iupper,
+ var, values, ierr)
else if (myid .eq. 1) then
ilower(1) = 0
ilower(2) = 1
iupper(1) = 2
iupper(2) = 4
do i = 1, 20
values(i) = 1.0
enddo
call HYPRE_SStructVectorSetBoxValues(b, part, ilower, iupper,
+ var, values, ierr)
do i = 1, 20
values(i) = 0.0
enddo
call HYPRE_SStructVectorSetBoxValues(x, part, ilower, iupper,
+ var, values, ierr)
endif
c This is a collective call finalizing the vector assembly
call HYPRE_SStructVectorAssemble(b, ierr)
call HYPRE_SStructVectorAssemble(x, ierr)
c-----------------------------------------------------------------------
c 6. Set up and use a solver (See the Reference Manual for
c descriptions of all of the options.)
c-----------------------------------------------------------------------
tol = 1.0E-6
if (precond_id .eq. 1) then
c PFMG
c Because we are using a struct solver, we need to get the object
c of the matrix and vectors to pass in to the struct solvers
call HYPRE_SStructMatrixGetObject(A, sA, ierr)
call HYPRE_SStructVectorGetObject(b, sb, ierr)
call HYPRE_SStructVectorGetObject(x, sx, ierr)
c Create an empty PCG Struct solver
call HYPRE_StructPCGCreate(MPI_COMM_WORLD, solver, ierr)
c Set PCG parameters
call HYPRE_StructPCGSetTol(solver, tol, ierr)
call HYPRE_StructPCGSetPrintLevel(solver, 2, ierr)
call HYPRE_StructPCGSetMaxIter(solver, 50, ierr)
c Create the Struct PFMG solver for use as a preconditioner
call HYPRE_StructPFMGCreate(MPI_COMM_WORLD, precond, ierr)
c Set PFMG parameters
call HYPRE_StructPFMGSetMaxIter(precond, 1, ierr)
call HYPRE_StructPFMGSetTol(precond, 0.0, ierr)
call HYPRE_StructPFMGSetZeroGuess(precond, ierr)
call HYPRE_StructPFMGSetNumPreRelax(precond, 2, ierr)
call HYPRE_StructPFMGSetNumPostRelax(precond, 2, ierr)
c Non-Galerkin coarse grid (more efficient for this problem)
call HYPRE_StructPFMGSetRAPType(precond, 1, ierr)
c R/B Gauss-Seidel
call HYPRE_StructPFMGSetRelaxType(precond, 2, ierr)
c Skip relaxation on some levels (more efficient for this problem)
call HYPRE_StructPFMGSetSkipRelax(precond, 1, ierr)
c Set preconditioner (PFMG = 1) and solve
call HYPRE_StructPCGSetPrecond(solver, 1, precond, ierr)
call HYPRE_StructPCGSetup(solver, sA, sb, sx, ierr)
call HYPRE_StructPCGSolve(solver, sA, sb, sx, ierr)
c Free memory
call HYPRE_StructPCGDestroy(solver, ierr)
call HYPRE_StructPFMGDestroy(precond, ierr)
else if (precond_id .eq. 2) then
c BoomerAMG
c Because we are using a struct solver, we need to get the object
c of the matrix and vectors to pass in to the struct solvers
call HYPRE_SStructMatrixGetObject(A, parA, ierr)
call HYPRE_SStructVectorGetObject(b, parb, ierr)
call HYPRE_SStructVectorGetObject(x, parx, ierr)
c Create an empty PCG Struct solver
call HYPRE_ParCSRPCGCreate(MPI_COMM_WORLD, solver, ierr)
c Set PCG parameters
call HYPRE_ParCSRPCGSetTol(solver, tol, ierr)
call HYPRE_ParCSRPCGSetPrintLevel(solver, 2, ierr)
call HYPRE_ParCSRPCGSetMaxIter(solver, 50, ierr)
c Create the BoomerAMG solver for use as a preconditioner
call HYPRE_BoomerAMGCreate(precond, ierr)
c Set BoomerAMG parameters
call HYPRE_BoomerAMGSetMaxIter(precond, 1, ierr)
call HYPRE_BoomerAMGSetTol(precond, 0.0, ierr)
c Print amg solution info
call HYPRE_BoomerAMGSetPrintLevel(precond, 1, ierr)
call HYPRE_BoomerAMGSetCoarsenType(precond, 6, ierr)
c Sym G.S./Jacobi hybrid
call HYPRE_BoomerAMGSetRelaxType(precond, 6, ierr)
call HYPRE_BoomerAMGSetNumSweeps(precond, 1, ierr)
c Set preconditioner (BoomerAMG = 2) and solve
call HYPRE_ParCSRPCGSetPrecond(solver, 2, precond, ierr)
call HYPRE_ParCSRPCGSetup(solver, parA, parb, parx, ierr)
call HYPRE_ParCSRPCGSolve(solver, parA, parb, parx, ierr)
c Free memory
call HYPRE_ParCSRPCGDestroy(solver, ierr)
call HYPRE_BoomerAMGDestroy(precond, ierr)
endif
c Free memory
call HYPRE_SStructGridDestroy(grid, ierr)
call HYPRE_SStructStencilDestroy(stencil, ierr)
call HYPRE_SStructGraphDestroy(graph, ierr)
call HYPRE_SStructMatrixDestroy(A, ierr)
call HYPRE_SStructVectorDestroy(b, ierr)
call HYPRE_SStructVectorDestroy(x, ierr)
c Finalize MPI
call MPI_Finalize(ierr)
stop
end